1. Ch.5, Sec.1 - What Are Earthquakes?
seismology – the study of earthquakes.
- the largest & most active earthquake zone lies along the plate boundaries surrounding the Pacific Ocean.
What Causes Earthquakes?
deformation – the bending, tilting, and breaking of the Earth’s crust; the change in the shape of rock in response to stress.

2. Ch.5, Sec.1- What Are Earthquakes?
- rock along a fault deforms in a plastic manner (molded clay) or in an elastic manner (rubber band).
- plastic deformation does not cause earthquakes!
- elastic deformation can cause earthquakes!
elastic rebound: the sudden return of elastically deformed rock to its undeformed shape.
Elastic Rebound video
- during elastic rebound, energy is released in the form of seismic waves & these cause earthquakes.

3. Ch.5, Sec.1 - What Are Earthquakes?

4. Ch.5, Sec.1 - What Are Earthquakes?
Faults at Tectonic Plate Boundaries
Plate Motion
Major Fault Type
Transform
strike-slip
Convergent
reverse fault
Divergent
normal fault
How Do Earthquakes Travel?
seismic waves: waves of energy that travel through the Earth, away from an earthquake in all directions.

5. Ch.5, Sec.1 - What Are Earthquakes?
- seismic waves that travel through Earth’s interior are called body waves.
- two types of body waves are P waves (pressure or primary) & S waves (shear or secondary). Pg.134
P waves: waves that travel through solids, liquids, and gases that cause particles of rock to move in a back-and-forth direction. (fastest type)
S waves: waves that travel slower than P waves and shear rock side-to-side.
- surface waves also occur & are very destructive!

6. Ch.5, Sec.1 - What Are Earthquakes?

7. Ch.5, Sec.1 - What Are Earthquakes?